Plastic blow molded bottles and the injection molded caps that snap onto them are designed for a secure fit that minimizes their chance of accidental separation during distribution and use. One example of such a bottle that is known for use as a container for shower gel is shown in FIGS. 1A and 1B. Bottle 10 includes a continuous snap ring 12 that extends a full 360°, without any voids, around a circumference of the neck. Snap ring 12 can be beveled on the top side so it functions like a barb for a cap to engage.
A snap-on cap 14 that can be used with bottle 10 of FIG. 1A is shown in FIGS. 2A, 2B and 2C. Cap 14 employs a four prong snap geometry that mates to the neck by slipping over snap ring 12. The prongs 16 are oriented 90° to each other and positioned to have an offset, α1, that is 45° from the part line 18 of the bottle (as measured from the midpoint of the prong), thus engaging the snap ring 12 on the neck in an intermittent manner at, for example, about where snap ring 12 intersects lines A, B, C and D, as shown in FIG. 1. One potential problem with this design is that it makes it difficult for the consumer to remove the cap if the bottle needs to be refilled.
Easy-off designs are known in the art for improving the ease with which a snap-on cap can be removed from a container. One example of such a design is shown in FIGS. 3A and 3B, which includes a bottle with six flower petal shaped tabs 30 positioned on the neck (three tabs on each side) and associated snaps 32 on the lid. A centering feature 34 aligns with gaps 36 in the lid. The centering feature 34 may provide leverage when twisting the cap that aids in removing the cap from the bottle. A similar flower petal design is employed in the conventional bottle and cap of FIGS. 4A and 4B.
FIGS. 5A and 5B show a conventional medicine bottle 10 that includes a snap ring 12 and an associated cap 14. The snap ring 12 extends nearly a full 360° around a circumference of the neck, with only a single void 13. Snap ring 12 can be beveled on the top side and functions like a barb for cap 14 to engage. Cap 14 employs a single snap 17 that mates to the neck by slipping over snap ring 12. The single snap 17 can be aligned with the void 13 to allow removal of the cap. This bottle and cap are designed to reduce the likelihood of accidental removal of the cap from the bottle 10, as the void is only about 5% or less of the total length of the circumference of the neck of the bottle.
The ability to refill bottles can potentially reduce waste production in the form of bottles disposed of by consumers. Thus, a novel bottle design that provides for ease of refilling the bottle would be a desired advancement in the art.